The next phase of the Brisbane Airport expansion is the construction of a reinforced concrete 4 lane underpass at Dryandra Road. The underpass allows vehicles to travel under the taxiways connecting the new runway to the existing Domestic and International terminals and runway systems. Dryandra Road will be realigned as part of the process and is due for completion in August 2018.
Brisbane Airport Corporation awarded the $120 million Dryandra Road Words contract to McConnell Dowell for this crucial infrastructure component on the new runway project. An estimated 700 precast concrete piles will be used, including 1.5 kilometres of roadway and portions of taxiway and airfield on top of the underpass structure.
McConnell Dowell contracted ASP Piling for the installation of sheet piles for the underpass. As stated by McConnell Dowell, the use of sheet piling will allow time savings due to reduced excavation, better construction access and stability. The largely sand site also meant that the use of sheet piling would be a stronger and more financially viable option when used in conjunction with the precast concrete piles.
ASP is contracted to install temporary retention walls for the main eastern and western shoring walls, the storm water pump station and the internal culvert. We mobilised sheet pile and drilling rigs and materials to site including over 1200 lineal metres of sheets ranging in lengths from 5 to over 10 metres. The size and profile of the sheets varied across the site based on client and engineering requirements including depth of the underpass.
ASP Piling set-out alignment of the sheet pile wall according to client and engineering specifications, pre-drilled and installed the sheet piles, and completed the excavation around sheets. The installation of temporary anchors to ensure the stability of the sheets throughout the construction of the underpass, including stressing the anchors to specified load parameters and de-stressing anchors when required will all be undertaken by ASP Piling’s highly skilled piling and anchoring staff.